How does the electric valve,motorized valve work

Motorized valve is composed of two parts in that part of the electric actuator, a part is the valve, the valve switch power from electric actuators, and there are two groups of travel switch on electric actuator, electric valve operation for the first time, need to set switch valve stroke, stroke after set, can achieve open electric actuators automatically stop when in place, locked in place after the electric actuators can also automatically stop, to achieve automatic control

1. The primary motor for electric valve is electric motor. Three - phase asynchronous motors specially designed. The motor is designed according to the short-time working system, with no cooling equipment, soft or soft mechanical properties. In the case of high reliability, a series of direct current motor is used. For places requiring change of speed, variable speed three-phase asynchronous motor is used.

2. The motor is slowed down by the main drive mechanism and the valve opening is driven. The structure of the main drive mechanism is more. The common structural form is the combination of worm wheel drive and spur gear transmission.

3. The torque of the main transmission mechanism is converted into thrust by trapezoidal thread, leading to the valve opening and closing (gate valve and globe valve) of linear motion. The stem nuts used for the general torque convertor are located on the stem as a part of the valve. The electric actuator outputs torque to drive stem nut.

4. For the valve (ball valve and butterfly valve) for the lifting and closing, the output shaft of the main transmission mechanism shall be driven by a secondary reducer to drive the valve opening. The secondary reducer usually adopts planetary gear transmission, worm gear drive and screw rocker transmission. The secondary speed reducer is usually installed in an independent housing and is assembled with an electric actuator.

5. Inside the main transmission mechanism, torque limitation mechanism, stroke control mechanism and valve position measuring mechanism are established. Torque limiter can be used to limit the output torque of electric actuators. The stroke control mechanism can be used to determine the valve opening position. The valve position gauge can provide the position signal of the valve in the form of analog quantity, and the supply operator monitors the valve opening in the distance, or supplies other automatic devices (regulators).

6. To operate the electric valve manually in case of necessity, a manual electric switching mechanism and handwheel are installed in the main drive mechanism. Manually cut the switching mechanism to manual side can use the handwheel to operate the electric valve. When electric, the motor is rotated and the switching mechanism is automatically cut to the electric side, which is operated by the motor (known as a semi-automatic switching mechanism).

7. The control circuit of the electric valve can operate the valve by starting the motor in accordance with the commands sent from the control panel or from the automation system. When the torque or stroke of the valve reaches the preset value, the control circuit can cut the power supply of the motor according to the signal of the torque limitation mechanism and the travel control mechanism. The control circuit also has protective function. When the motor is overloaded or other faults occur, it can automatically cut off the power and send out the alarm signal.